XivCommon/XivCommon/Functions/Talk.cs

using System;
using System.Runtime.InteropServices;
using Dalamud.Game;
using Dalamud.Game.Text.SeStringHandling;
using Dalamud.Hooking;
using Dalamud.Plugin.Services;

namespace XivCommon.Functions;

/// <summary>
/// Class containing Talk events
/// </summary>
public class Talk : IDisposable {
    private static class Signatures {
        internal const string SetAtkValue = "E8 ?? ?? ?? ?? 41 03 ED";
        internal const string ShowMessageBox = "4C 8B DC 55 57 41 55 49 8D 6B 98";
    }

    // Updated: 5.5
    private const int TextOffset = 0;
    private const int NameOffset = 0x10;
    private const int StyleOffset = 0x38;

    private delegate void AddonTalkV45Delegate(IntPtr addon, IntPtr a2, IntPtr data);

    private Hook<AddonTalkV45Delegate>? AddonTalkV45Hook { get; }

    private delegate IntPtr SetAtkValueStringDelegate(IntPtr atkValue, IntPtr text);

    private SetAtkValueStringDelegate SetAtkValueString { get; } = null!;

    /// <summary>
    /// The delegate for Talk events.
    /// </summary>
    public delegate void TalkEventDelegate(ref SeString name, ref SeString text, ref TalkStyle style);

    /// <summary>
    /// <para>
    /// The event that is fired when NPCs talk.
    /// </para>
    /// <para>
    /// Requires the <see cref="Hooks.Talk"/> hook to be enabled.
    /// </para>
    /// </summary>
    public event TalkEventDelegate? OnTalk;

    internal Talk(ISigScanner scanner, IGameInteropProvider interop, bool hooksEnabled) {
        if (scanner.TryScanText(Signatures.SetAtkValue, out var setAtkPtr, "Talk - set atk value")) {
            this.SetAtkValueString = Marshal.GetDelegateForFunctionPointer<SetAtkValueStringDelegate>(setAtkPtr);
        } else {
            return;
        }

        if (!hooksEnabled) {
            return;
        }

        if (scanner.TryScanText(Signatures.ShowMessageBox, out var showMessageBoxPtr, "Talk")) {
            this.AddonTalkV45Hook = interop.HookFromAddress<AddonTalkV45Delegate>(showMessageBoxPtr, this.AddonTalkV45Detour);
            this.AddonTalkV45Hook.Enable();
        }
    }

    /// <inheritdoc />
    public void Dispose() {
        this.AddonTalkV45Hook?.Dispose();
    }

    private void AddonTalkV45Detour(IntPtr addon, IntPtr a2, IntPtr data) {
        if (this.OnTalk == null) {
            goto Return;
        }

        try {
            this.AddonTalkV45DetourInner(data);
        } catch (Exception ex) {
            Logger.Log.Error(ex, "Exception in Talk detour");
        }

        Return:
        this.AddonTalkV45Hook!.Original(addon, a2, data);
    }

    private void AddonTalkV45DetourInner(IntPtr data) {
        var rawName = Util.ReadTerminated(Marshal.ReadIntPtr(data + NameOffset + 8));
        var rawText = Util.ReadTerminated(Marshal.ReadIntPtr(data + TextOffset + 8));
        var style = (TalkStyle) Marshal.ReadByte(data + StyleOffset);

        var name = SeString.Parse(rawName);
        var text = SeString.Parse(rawText);

        try {
            this.OnTalk?.Invoke(ref name, ref text, ref style);
        } catch (Exception ex) {
            Logger.Log.Error(ex, "Exception in Talk event");
        }

        var newName = name.Encode().Terminate();
        var newText = text.Encode().Terminate();

        Marshal.WriteByte(data + StyleOffset, (byte) style);

        unsafe {
            fixed (byte* namePtr = newName, textPtr = newText) {
                this.SetAtkValueString(data + NameOffset, (IntPtr) namePtr);
                this.SetAtkValueString(data + TextOffset, (IntPtr) textPtr);
            }
        }
    }
}

/// <summary>
/// Talk window styles.
/// </summary>
public enum TalkStyle : byte {
    /// <summary>
    /// The normal style with a white background.
    /// </summary>
    Normal = 0,

    /// <summary>
    /// A style with lights on the top and bottom border.
    /// </summary>
    Lights = 2,

    /// <summary>
    /// A style used for when characters are shouting.
    /// </summary>
    Shout = 3,

    /// <summary>
    /// Like <see cref="Shout"/> but with flatter edges.
    /// </summary>
    FlatShout = 4,

    /// <summary>
    /// The style used when dragons (and some other NPCs) talk.
    /// </summary>
    Dragon = 5,

    /// <summary>
    /// The style used for Allagan machinery.
    /// </summary>
    Allagan = 6,

    /// <summary>
    /// The style used for system messages.
    /// </summary>
    System = 7,

    /// <summary>
    /// A mixture of the system message style and the dragon style.
    /// </summary>
    DragonSystem = 8,

    /// <summary>
    /// The system message style with a purple background.
    /// </summary>
    PurpleSystem = 9,
}